Our Oversized Groundwater Footprint

[polly7]

Published Aug 13 2012 by National Geographic Newswatch, Archived Aug 15 2012

http://www.energybulletin.net/stories/2012-08-15/our-oversized-groundwater-footprint

by Sandra Postel

We don’t see it, smell it or hear it, but the tragedy unfolding underground is nonetheless real – and it spells big trouble.

I’m talking about the depletion of groundwater, the stores of H2O contained in geologic formations called aquifers, which billions of people depend upon to supply their drinking water and grow their food.

For a long time, we had only a vague sense of the scale of this depletion, mostly through anecdotal evidence and selected country studies. While researching my 1999 book Pillar of Sand, I gathered the best data I could find at the time, and with all the necessary caveats, estimated that about 8-10 percent of the world’s food supply depended upon the draining of underground aquifers.

About a decade later, modeling work by Marc Bierkens of Utrecht University in the Netherlands and his colleagues arrived at a global depletion estimate that produced a similar figure: their estimated 283 billion cubic meters of groundwater depleted in 2000 is sufficient to produce 188.6 million tons of grain, equal to 10 percent of that year’s global grain production. While not all groundwater pumped from the earth is used to produce grain, the vast majority of it is.

In recent years a number of other studies, along with NASA’s GRACE (Gravity Recovery and Climate Experiment) mission, have corroborated the dangerous trend. From the Arabian deserts to the North China Plain, and from the breadbasket of India to the fruit and vegetable bowl of the United States, we are increasingly dependent on the unsustainable use of groundwater.

In effect, we’re robbing the Peters of the future to feed the Pauls of today. more ....

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[pscot]

1. You don't miss the water

'til the well runs dry.